A ternary Nickel foam (NF)–graphene/MnO2/polyaniline (PANI) nanocomposite has been synthesized using green chemistry approach (in situ polymerization). All reactants were dispersed homogeneously in precursor solution in the form of ions and molecules. PANI and MnO2 molecules on the NF–graphene contact each other and are arranged alternately in the composite. Alternative arrangement of PANI and MnO2 nanoparticles separates them and prevents the aggregation of PANI and MnO2 to decrease the particle size of the composite on the surface of NF–graphene. The intermolecule contact improves the conductivity of the composite. The composite showed excellent specific capacitance of 1081 F/g at a scan rate of 1 mV/s and specific capacitance of 815 F/g at a current density of 3 A/g, having excellent cycling stability. Current study provides an alternative pathway to improve the rate capability and cycling stability of nanostructured electrodes, by offering a great promise for their applications in supercapacitors.